Question

The research conducted by Tilman and colleagues demonstrated that a. as diversity increases, productivity increases. b. as diversity decreases, productivity increases. c. areas with higher diversity demonstrate less efficient use of nutrients. d. increases in species richness lead to an increase in invasive species. e. increased diversity results in increased susceptibility to disease.

Short answer

The correct answer is (a) 'as diversity increases, productivity increases'. This aligns with the findings of the study conducted by Tilman and colleagues.

Step-by-step solution

Review the Study

To solve this exercise, the content of the study conducted by Tilman and colleagues needs to be understood. Their research was on the effects of biodiversity on the functioning of ecosystems. The important conclusion was that biodiversity enhances the performance of ecosystem, including productivity.

Analyze the Options

Go through all the options: (a) as diversity increases, productivity increases. (b) as diversity decreases, productivity increases. (c) areas with higher diversity demonstrate less efficient use of nutrients. (d) increases in species richness lead to an increase in invasive species. (e) increased diversity results in increased susceptibility to disease. Compare these options with the content of the study to select the most accurate one.

Choice Selection

Upon analysis, it can be seen that option (a) 'as diversity increases, productivity increases' aligns with the findings of Tilman and colleagues. The study claimed that biodiversity enhances the performance of ecosystem, including productivity.

Key concepts

Ecosystem Functioning

Ecosystem functioning refers to the natural processes and interactions that maintain the health and balance of ecosystems. These processes include energy flow, nutrient cycling, and various ecological interactions such as predation, competition, and mutualism. When an ecosystem functions well, it can support diverse life forms, maintain stability, and withstand environmental changes. The study by Tilman and colleagues underscores that ecosystems with higher biodiversity tend to function more efficiently, as diverse species contribute different roles and traits that improve the ecosystem's ability to cope with stresses and disturbances. Biodiversity helps enhance ecosystem functioning by promoting resilience, offering more ecological niches, and improving resource use efficiency.

Species Richness

Species richness is a measure of the number of different species present in an ecosystem. It is a major component of biodiversity. Higher species richness often indicates a healthy and robust ecosystem. Each species plays a unique role in its ecosystem, contributing to its overall functioning and productivity.

• Species richness enhances pollination and seed dispersal;
• Facilitates complex food webs;
• And increases ecosystem stability.

In the research by Tilman and colleagues, it was evident that increased species richness leads to more efficient ecosystem functioning. This is because a higher number of species can lead to a variety of ecological functions which, in turn, makes the ecosystem more productive and resilient.

Productivity

Productivity in an ecosystem refers to the rate at which plants and other photosynthetic organisms produce organic compounds in an ecosystem. This process is essential as it forms the basis of the food chain. The productivity of an ecosystem is determined by factors such as climate, availability of resources, and biodiversity. A diverse ecosystem tends to have higher productivity because:

• Different species can exploit different niches;
• Multiple species can complement each other's resource use;
• And there is a greater potential for more robust biological interactions.

Research by Tilman and colleagues confirms that ecosystems with higher species diversity tend to be more productive. They found that as species diversity increases, so does ecosystem productivity, because of improved nutrient uptake and more efficient use of available resources.

Nutrient Use Efficiency

Nutrient use efficiency refers to the ability of an ecosystem to utilize available nutrients for growth and maintenance without waste. This efficiency is crucial for sustaining ecosystem productivity and health. In ecosystems with high biodiversity, species often vary in their nutrient needs and acquisition strategies, which can lead to a more complete use of available nutrients. A few important aspects of nutrient use efficiency include:

• Efficient nutrient cycling reduces the need for additional nutrient inputs;
• Different plants may utilize various forms of the same nutrient;
• Diverse root systems can access nutrients from different soil depths.

Tilman and colleagues found that ecosystems with greater species diversity tend to use nutrients more efficiently. This is because each species can tap into different resources, minimizing waste and promoting more balanced nutrient cycling across the ecosystem.